Electric fuse



A. W. STEELE.

ELECTRIC FUSE.

APPLICATION FILED JULY 5, 1919.

Patented Aug. 2, 1921.

INVENTOR UNITED STATES PATENT or nca.

ARCHIE W. STEELE, OF BLO0MFIELD, NEW JERSEY, ASSIGNOR TO WILFORD '1'. HAWKINS, OF MONTGLAIR, NEW JERSEY.

nnncraic rnsn'.

Specification of Letters Patent.

Patented Aug. 2, 1921.

Application filed July 5, 1919. Serial No. 308,842.

['0 all whom it may concern:

lie it known that I, ARCHIE W'. STEELE, a subject of the King of Great Britain, resid- .ing at Bloomfield, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements in Electric Fuses, (Case 13;) and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to electric fuses, particularly fuses 'of the renewable type. The object of the invention is to provide an electric fuse of an improved construction, such that the fuses may be manufactured at low cost and may be readily opened and reassembled for the purpose of removing the parts of a ruptured fuse and substituting a new fuse in its place. Preferably the improved construction embodies the invention disclosed in-an application for patent filed by me on May 242, 1919, Serial No. 299,519, including a plate at one or both ends of the tube of the fuse lying in a slot in the end of the tube and screws for drawing this plate toward the end of the end cap to expand the walls of the tube to move them into tight engagement with the interior surface of the end ca and thus bind all of the parts together. he preferred embodiment of the present invention is illustrated in the accompanying drawingdn which Figure 1 is a central longitudinal section of the fuse; Fig. 2 is a central longitudinal section on a plane at right angles to that of Fig. 1;

Fig. 3 is a transverse section on line 3--3 of Fig. 2; Fig.4 is a perspective view of one of the plates; Fig 5 is anelevation of the tube; Fig. 6 is a view similar to Fig. 2 illustrating a slightly modified construction, and Fig. 7 isa View corresponding to Fi 4 and illustrating the tube of Fig. 6.

. Feferring to these drawings, the fuse includes a tube 8 of fiber or other suitable insulating material. At each end this tube has a slot cutetherein, the side walls of which are inclined as is clearly illustrated in'Fig. 5.

The fusible link and the parts for supporting it and making electrical connection to it may be assembled as a unit and when so assembled may be mounted withinthe tube 8. For this purpose a strip 9 of insulat ng material is employed in combination with two fuse terminals 10, the insulating strip 9 extending throughout the length of and parallel to the fusible link 11 and the termiuals 10 being secured to the ends of the strip 9 in electrical connection with the ends of the link 11. The fuse terminals 10 are strips of copper whose outer ends are adaptedto coact with switch clips by which the fuse is connected in the circuit. These terminals 10 are secured to the ends of the strip of insulating material 9 by bolts 12 and nuts 13 and if desired, pins may be driven through the strip 9 and terminals 10 to prevent the terminals from turning about the axis of the bolts 12. These bolts 12 also pass through holes or slots in the ends of the fusible strip 11. By this construction, tightening up the bolts 12 and nuts 13 effects good electrical connection of the endsof the fuse 11 to the terminals 10 and all of these parts are securely fastened to the insulating strip 9 which serves as a. support and relieves the flexible and relatively weak strip 11 from. strains to which it would otherwise be subjected.

In order to mount within the tube the unit consisting of the parts 9, 10 and 11, plates 14 are preferably employed lying in the slots at the ends of the tube 8 and adapted to be secured to end caps 15 in closing the ends of tube Preferably each of the terminals 10 has notches cut into .opposite edges as shown in Fig. 2. Each plate 14: has a central slot as shown at 16 in Fig. 4 of a width corresponding to the terminal .1 10, and also two threaded openings 17 to receive screws passing through the end cap 15. I

When the unit consisting of the parts 9, 10 and 11 has been assembled, it is inserted within the tube 8 and held in position therein. Then a plate 14. is moved into each of the slots in the ends of tube 8, the terminal 10 passing into the slot 16 of the plate. Then an end cap 15 is passed over the protruding end of the terminal 10 and the end of the tube 8, the'end cap being provided with a slot corresponding in size to the cross-section ofthe terminal 10. This having been done, screws 18 are inserted through the holes in the end cap and threaded into the openings 17 in the plate 14. As

these' screws are tightened up, the. plate 14L plate 14 is so moved bodily toward the end of the end cap, its inclined side walls 19 cothan a screw driver, it being necessary only to remove the screws 18 whereupon the end caps 13 and plates 14 may be removed and the entire unit consisting of the parts 9, 10 and 11 can be taken out of tube 8 for the purpose of substituting a new fusible link for the parts of the disrupted one.

The construction above described may be modified slightly in accordance'with Figs. 6 and 7, this modification involving merely the omission at one end of the fuse, of the plate 14, the screws 18 and the slot in tube 8 in which the plate 14 is received In all other respects the construction is like that illustrated in the preceding figures. The terminal 10 at the end of the fuse where the plate 14 is omitted, need not be provided with notches in opposite edges as in the case of the terminalat the other end of the fuse. Instead, its width may be slightly reduced as shown in Fig. 6 so that the portion lying within tube 8 is of a width corresponding to the width of the strip 9 and the end portions of the fusible link. The slot in the end cap 15 may be of the size of the larger portion of the terminal 10 as shown in Fig. 6 in which case the terminal 10 may be moved through it and the unit carrying the fusible link withdrawn from within tube 8 without removing the end cap 1 5 which is frictionally or otherw1se secured to the tube 8. On

.the other hand, the slot in the end cap 15 may be of the size of the smaller portion of this terminal 10 -in which case the smaller end of terminal 10 would be passed through the slot in the end cap before securing the terminal to the strip 9, and the removal of the unit carrying the strip 11 from within tube 8 would be effected by moving the unit in the opposite direction and carrying the end cap 15 with it.

I claim: I 1. An electric fuse comprising a tube of insulating material having slots in its ends,

a unit consisting of a fusible link and a strip of insulating material extending parallel to each other, and two fuse-terminals secured to the ends of the link and strip, said unit being mounted within the tube with the terminals projecting beyond the ends thereof, plates lying in said slots and arranged to receive the terminals, said plates having inclined walls cooperating with the walls of said slots, end caps on the ends of the tube and screws passing through the ends of the end caps and engaging threaded openings in the plates.

2. An electric fuse comprising a tube of insulating material, a fusible link within the tube, a strip of insulating material in the tube extending parallel to the link, terminals secured to the ends of the strip and link and extending beyond the ends of the tube, end caps on the ends of the tube having slots through which the terminals extend, a plate provided with a central slot through which one of the terminals extends, said plate lying in a slot in one end of the tube and having inclined side walls cooperating with the walls of said slot and means for drawing said plate toward the end of the end cap and thereby expanding the end of the tube on opposite sides of the slot therein to cause the tube to grip the interior of the end cap.

.In testimony whereof I aflix my signature.

ARCHIE \V. STEELE. 

